Glue machine



June 1, 194-3. BOWLING 2,320,715

GLUE MACHINE Filed Jan. 13, 1941 8 Sheets-Sheet 1 3 ROBERT T. BOWLING INVENTOR ATTORNEY 8 Sheets-Sheet 2 N S T. BOWLING INVENTOR ATTORNEY Juhe 1, 1943. R. T. BOWLING GLUE MACHINE Filed Jan. 13, 1941 June 1, 1943. BOWLING. 2,320,715

GLUE MACHINE I mmm INVENTOR ATTORNEY ROBERT -T.. BOWLING June 1, 1943. R. T. BOWLING GLUE MACHINE 8 Sheets-Sheet 4 8 ROBERT -T. BOWLING iNVENTOR v W'M n ATTORNEY Filed Jan. 13, 1941 June 1, 1943; -R. T. BOWLING 2,320,715

GLUE MACHINE Filed Jan. 15, 1941 8 Sheets-Sheet 5 I [7T] II III ROBERT T. BOWLING INVENTOR ATTORN EY June 1, 1943.

R. T. BOWLING GLUE MACHINE Filed Jan. 15, 1941 8 Sheets-Sheet 6 FIG. /2

ATTORNEY June 1, 1943. R. T. BOWLING GLUE MACHINE 8 Sheets-Sheet 7 Filed Jan. 13, 1941 INVENTOR ROBWBOWLI NG ATTORNEY June 1, 1943. R, BOWLING 2,320,715

GLUE MACHINE Filed Jan. 13, 1941 s Sheets-Sheet 8 ROBERT T. BOWLING INVENTOR ATTORNEY Patented June 1, 1943 GLUE MACHINE Robert T. Bowling, Lewiston, Idaho, assignor' to Potlatch Forests, Inc., Lewiston, Idaho Application-lanuary 13, 1941, Serial No. 374,232

1 Claim.

This invention relates to improvements in glu ing machines designed for use in. lumber mills or other lumber fabrication establishments for joining narrow boards to form wide panels, or to join boards of relatively short lengths to form comparatively long panels.

Often in growth, the tree from which the log is out has sufiered injury from lightning or bruising, or it has been injured by disease or ravaged by pests or, and this is more common, it may be faulty due to its having too many knots scattered throughout its length and width. In the conventional lumber mill, a log is ripped or sawn ness or a combination of both, of course, determines largely the value of the lumber. This value increases in direct proportion to the width as regards any given thickness. For example, one-inch lumber twelve inches wide may be worth forty dollars a thousand board feet. of the same grade and quality of lumber, but increasing in width an inch may well be fifty doliars per thousand board feet. This increase quite naturally follows with wider widths, until sixteen-inch boards, of the same quality and grade :1

that sold for forty dollars a thousand board feet a in the twelve-inch width, are valued at eighty dollars per thousand board feet. It can be seen The price i;

that in lumbering operations, where logs furnished do not permit the cutting of wide lumber for which there is a constant demand in construction, an operator can convert his lower value lumber and raise its quality and grade. It is often this raised value that can make the diiference between a loss and a profit On the operation.

Heretofore, it has been practically impossible toform by gluing, wide lumber panels out of narrow strips because of the inferior quality of the glue that was economically available for such use. made such an operation uneconomical and beyond practical possibility. In recent years a great variety of very fine glues and adhesives have been developed. For example, those of the phenolic-resin type, when properly applied to Suitable glue. because of its great cost,

lumber, bond with the lumber and permit the adhesion of two pieces so firmly that where the glued joint is formed, there is greater strength than has the inherent strength of the lumber itself. Thus there arose a need and a desire for machinery which is usable for Joining a plurality of strips together in a fast, efficient operation to produce wide boards.

, It is a prime object and purpose of this invention to provide a method of joining side by side narrow or short strips of lumber together to produce relatively wide and long panels having a greater value per board foot than the value of the individual pieces fromwhich the panel is formed.

Another object of my invention has been the provision of a gluing machine adaptable for use in joining such narrow or short boards in the practice of this method that I have devised.

It is to be borne in mind that in the lumber business when a rough plank has been ripped from the log it is then passed to a grading table which is provided with a plurality of rip saws which can be set at various positions across the width of the table. When the board is moved thereover it will beripped to a variety of widths, according to the best judgment of the operator of the grading table. For example, out of a rough cut twenty-four-inch plank there may be out two six-inch boards, an eight-inch board and a four-inch board. These can be sorted according to size into piles so that a standard gluing machine adapted for that particular size would permit their joinder to form wide glued panels. It would, however, be uneconomical to have to have a machine for only a single width of lumber. It has, therefore, been a further and an important object of my invention to provide a gluing machine adaptable to gluing varying widths of lumber that may be presented to it for longitudinal edge or end gluing.

It is often desirable during the operation of preparing the lumber for gluing to plane the edges and apply thereto the adhesive that will be later used in the actual gluing operation. This preparatory work may, with certain glues, be

accomplished hours or even days before the actual gluing operation takes place. The adhesive will set or harden during such an intermediate interval of time and it becomes necessary, when the actual gluing takes place, to prepare the lumber by preheating it so that when it is introduced to a gluing machine and side, top and bottom pressure is applied, the glue will readily soften and be absorbed or bond into the joined pieces of lumber.

It is therefore another important object of this invention to provide a gluing machine adaptable to gluing previously prepared wooden boards and said machine having, as associated parts thereof, preheater means and an assembly table whereon the lumber may be prepared for the final gluing operation.

It is also advisable during the actual gluing op eration of long, relatively narrow strips of lumber, toapply lateral as well as vertical pressure upon the joints being glued, as well as to apply heat to those joints simultaneously with the application of pressure to effect a lasting and secure bondin of the pieces of material being glued.

It is therefore still another object of this in vention to provide, in a gluing machine, a heater means associated with the vertical pressure means for applying heat to the joints being glued and this application is to be performed simultaneously with the pressure operation.

A still further object of this invention has been to provide a "Spot-pom heater for the joints being glued, which heater is associated with the pressure means and movable into and out of contact with the lumber being glued simultaneously with the application of pressure.

Other and important objects of the invention will be apparent during the course of the following description.

In the drawings I have shown a preferred form of my invention, constructed and assembled in accordance with my present practice. The inventive idea is capable of receiving a variety of mechanical expressions, one of which, for the purpose of illustrating the invention, is shown in the accompanying drawings, and described hereafter in the detailed description thereof. In the-drawings,

Figure 1 is a plan view of the gluing machine of my invention, illustrating the general assembly and arrangement of parts employed therein,

Figure 2 is an enlarged fragmentary side elevational view of the machine of Figure 1, showing the left end thereof,

Figure 3 is an enlarged fragmentary end elevational view of the machine of Figure 1, showing the right end thereof,

Figure 4 is a vertical, sectional view taken on line L4 of Figure 1, and with portions broken away for convenience of illustration,

Figure 5 is an enlarged detail view of a traveler nut and the side pressure bar employed in my gluing machine, and the showing is somewhat enlarged over that of Figure 4,

Figure 6 is a vertical, sectional view taken through the pressure nut of Figure 5 on line 8--6,

Figure '1 is a fragmentary, vertical sectional view, enlarged and as though taken on line 11 of Figure 1,

Figure 8 is a fragmentary, side elevational view of a pressure bar and of the actuator eccentric shown in Figure '1.

Figure 9 is a vertical, fragmentary sectional view taken on line 9-9 of Figure 7,

Figure 10is a detail sectional view taken on line Ill-I0 of Figure 9,

Figure 11 is a vertical sectional view through an upper vertical pressure bar and heater element and through a portion of the opposed lower pressure bar,

Figure 12 is a side elevational view of a fragment of an upper pressure bar, and showing thereon a nut employed in cooperation with the chine.

Figure 13 is a perspective'view of a heater element clip employed in my heater,

Figure 14 is a detail view, partially in cross section, as thoughtaken on line I4l4 of Figure 15,

Figure 15 is a detail plan view illustrating the lateral adjustment arrangement for the pressure bar of my gluing machine, with portions omitted for convenience of illustration,

Figure 16 is a fragmentary perspective view of an end section of a glued panelproduced according to the practices of the principles of my invention,

Figure 17 is a fragmentary perspective end view of an alternate form of panel board which may be produced according to the principles of my invention,

Figure 18 is a plan view of an assembly table and preheater arrangement employed in connection with my gluing machine,

Figure 19 is a fragmentary elevational view of the end of the table of Figure 18 as though taken along the plane indicated by line ill-l9,

Figure 20 is a fragmentary, vertical sectional view taken on line 20-20 of Figure 18,

Figure 21 is an enlarged fragmentary, sectional view through a heater element of the assembly table, showing associated therewith a board for preheating preparatory to being introduced to the gluing machine.

The frame of my gluing machine comprises a plurality of vertical legs 25, which are arranged in opposed pairs along the length of the machine.

These legs are joined crosswise of the machine at their upper ends by means of lateral header members 26, 28. The lower portions of the legs 25 are also Joined by lateral supports 28 upon which rest the lower heater members employed in my gluing machine. Longitudinally of the machine I employ stringers 21 which tie the pairs of legs together and roughly define a rectangular structure.

Disposed in the central portion of the machine and resting on the lateral supports 28 are a plurality of lower longitudinal pressure bars 30. In juxtaposition thereover is an aligned set of opposed pressure bars 3|. As may best be seen in Figures 11 and 12, the pressure bars 30 and 3| are shown as comprising I-beams or other similar rigid structural shapes.

Each pressure bar has on one face an insulator block 32 which may be formed of transite or other similar material. In the upper face of block 32 I have provided grooves 33 A cooling conduit 34 is positioned in each groove. The block 32 is secured to the flange of the member 30 or 3| by means of fillister screws 25.

In the contact face of the block 32 I provide a longitudinal groove 38 and a heater cable 31 is fitted therein. Cables 31 are retained in place by means of the clips such as 38 shown in Figure 13. Clip 38 has end holes 39 through which the shank of bolt is passed and the clip is held in place by the head of the screw or bolt 35.

It is to be noted that the pressure bars at and 3| and the heater element 31 supported thereon are to be brought into position immediately adjacent a joint between boards that are being glued in the machine. The upper pressure bar's 3| are movable vertically in order to permit the introduction of materials to be glued between them and bars 30. All pressure bars are adjustable laterally of the machine to accommodate varying widths of material that is being glued.

As'may best be seen in Figures 1 and 1,5, the

machine is provided at one end with a plurality of bars-44, 45, 46 and 41 are positioned at a remote point or near the tail end of the machine.

Directly below the adjusting screw 49, 4|, 42 and 43 is provided a. similar group of aligned screw bars 48, 49, 69 and as are shown in Figure 2 In Figure 3 may be seen a fourth group of screw bars 52, 53, 54 and 55, which are aligned with the upper bars 44, 45, 48 and 41 on the tailing end of the machine. w

The adjustment screw bars 49, 41, 48 and 65 are joumaled in bearings 56 which are secured to tructural stringers of the machine frame. Bearlugs 66 have substantial length and thus position the sprockets 51 on the bars, 49, 41, 49 and 56 some distance outward from the machine. Similarly screw bars, 4|, 46, 49 and 54 are journaled in bearings 59, shorter than bearings 56, to position sprockets 59 between the machine frame and the plane of sprockets 51. In like manner screws 42, 45, 59 and 53 are journaled in still shorter bearings 89 to position sprockets 6| on the shafts journaled therein in a plane inside that of both sets of the sprockets 51 or 59. The remaining screw bars 49, 44, 5| and 55 are journaled in the shortest bearings 62 to position sprockets 63 in an inner plane closely parallel to the machine side stringer to which the bearings may all be attached.

The screw bars of each group are of varying length and extend inwardly of the machine at right angles to the pressure bars 39 and 3|, each of which has pairs of lead nuts 65 into which a screw bar is threaded. Rotary movement of the screw adjusting bars will move the pressure bars laterally of the machine to permit positioning as desired by the operator.

Each of the sprockets 51 is encircled by a chain 66 and similarly, all sprockets 59 are encircled by chain 61, all sprockets 6| by chain 68, and all sprockets 62 by chain 63.

Screw bars 41, 46, 42, 43 are all extended beyond their respective sprocket a distance sufflcient to permit the attachment thereto respectively of the hand wheels 19, 1|, I2 and 13.

The upper end of each leg 25 is slotted at 15 'and provided with paired guide blocks 16 for the reception of a vertically slidable bearing block 11. The trunnions 18 of a plurality of eccentric shafts 19 are journaled in these bearing blocks. A presser block 89 rests on each bearing 11, and positioned thereabove in slot 15 is an upper spring seat block 8|. Seated against each member 89 'and each member 8| is an expansible spring 82 which applies tension against the bearing blocks 11 to retard or dampen upward movement thereof. A bolt 83 is threaded into a head block 84 of each leg and bear upon block 9| to. permit the raising and lowering of that member to vary tension of the spring 82.

Each separate eccentric shaft 19 passe laterally through each upper pressure bar 3| which has cheek bearings 85 and 86 to provide adequate bearing surface for the eccentric shaft in its function. On an outboard end of each eccentric shaft is secured a sprocket 81.

Supported in said machine frame and longitudinally thereof are horizontal plates 88 which are slotted at 89 and have edge lips 99 to form guide grooves for a carriage nut 9I having side guide flanges 92 that fit into' the guide grooves. The

carriage nuts are arranged in pairs spaced along the length of the machine at suitable intervals andare threadedly engaged on a lateral side pressure screw 94 that is iournaled in the machine frame for rotation. An outboard end of each screw 94 has a sprocket 95. Chain 93 encircles the sprockets 81 and 95.

Parallel to the machine frame along one side I provide an auxiliary frame comprising supports 96 and spaced stringers 91. On the stringers 91 in association with each side'pressure screw I mount a speed reducer 99, designated thus as a whole. The drive shaft of each speed reducer device is joined to the adjacent screw by a coupler 99. The driven shaft of each speed reducer is coupled longitudinally ofthe machine by shafts I99 and MI, and motor I92 drives these shafts to turr. the screws 94.

On the cross headers 26 and longitudinally of the machine, I mount head stringers II9, which are paired in spaced apart relation. At either end on their lower sides, stringers II9 have guide lips I I I. Journaled between pairs of stringers I I9 are longitudinal and pressure screws H2 and H3. Each screw is provided with a sprocket II4. 0n suitable supporting cross members 6 above the stringers I I9, I mount a gear case H6 which has secured to one side thereof the motor II1. 0n

.the driven shaft II8, protruding from the gear case, I mount the sprocket H9. The drive chain I29 encircles sprockets H4 and H9 to impart rotary motion to the and pressure screws 2 or- I24 which has disposed therein vertically slidable end pressure bars I25. A depending link I26 is connected to the top end of each pressure bar and the upper end of each link at I21 is engaged in a slot (not shown) in a pivoted arm I28. The arm I28 is hinged for swinging movement at I29 to an anchored plate I39. The upper end of each traveler nut I2I or I22 is provided with a boss I3I which extends upwardly between the stringers I I9 and above the upper surface thereof to contact the lower face of the swinging arm I28,

The end pressure mechanism thus far described is that disclosed on the feed end of'the machine, and it will be understood that the tailing end of the machine is provided with the same general structure. The screw threads on opposite ends of the pressure screws II 2, H3 are cut opposite to each other so that when rotary motion is. applied to the screw bar, the opposed end pressure dev ces will move toward each other or .away from each other, as the case may be. Thus they either exert closing pressure or withdraw out of the way to permit the removal of a glued panel.

On the feedend of the gluing machine I provide an assembly and preheater table which compr'ses vertical supporting legs I49 having upper cross bars I4I. Side rails I42 are secured to the ends of the cross bars MI and by means of bearings I43, a shaft I44 is mounted for rotation ad-.

jacent that end of the assembly table frame that is nearest the gluing machine. Sprockets I45 are secured to theshaft I44 which also has a drive sprocket I46.

On the opposite end of the frame I mount for sliding movement, the bearings I41 in the slots I48. Each bearing is provided with a screw bar I49 that passes through a flange I56; and, by means of nuts I5I, the position of the bearings I41 in the slot I48 can be altered. The shaft I520. is journaled in tie bearings I41 and has, on each outer end, a sprocket I52 aligned with the opposed sprockets I45. The link chains I53 each encircles a sprocket I45 and I52 and rest upon the upper surface of the stringers I42.

A cross bar I54 has end ears I55 that are secured to the chains I53. These ears also rest upon the stringers I42 for sliding movement. An upstanding flange I56 is disposed between the chains I53 to serve as a pusher bar to clear the upper surface of the assembly table.

As can best be seen in Figure 20, angle irons I66 are arranged vertically on their flanges and joined together to form an assembly table surface I6I having slots I62 lengthwise thereof. Resting on the cross bars I in alignment below the slots I62, are longitudinal grooved heater blocks I64, each of which has a cable heater element I65. The blocks I64 are preferably of insulating material. The tailing end of the assembly table may be attached to the vertical legs of the gluing machine by means of clips I66.

On the tailing end of the gluing machine, as can best be seen in Figure 3, I mount horizontal bars I16 which are supported by legs HI and which support the upright flanged spaced-apart guide legs I12 and I13. Mounted rigidly between the flanges in the lower portion of the legs I12, I13, is a bearing I14 for the shaft I15. A tailing roller I16 is mounted on the shaft I15 which shaft also has a drive sheave I11 engaged by the belt I16 that is driven from the sheave I16 on the drive shaft of the motor I66.

Above the roller I16 I mount a vertically movable roller I6I on the shaft I62. Shaft I62 is journaled in slide bearings I63 between the flanges of legs I12, I13. The slide bearings are under the urgence of a spring suchas I64. An adjustment screw I85 cooperates with follower block I86 against which the upper end of each spring I64 is seated. By depressing or releasing the tension on the spring, an operator can increase or decrease the resiliency of the pressure roller I 9|. A vertical leg I96 and a cross head I6I mount stringers I92 for supporting a tailing roller I63 mounted for rotation on the shaft I94. A plurality of rollers such as I93 can be also mounted at spaced intervals along stringers I92 to form a roller table for the panels as they leave the gluing machine.

Lateral adjustment of longitudinal pressure bars The juxtaposed tiers of longitudinally extending pressure bars 66 and 3| are laterally adjustable in parallel horizontal planes in the machine. Each lower and its opposed upper pressure bar moves in this lateral adjustment together and, at all times, in alignment.

Referring to Figure 14, it will be seen that the adjustment screw 43 is threadedly engaged in a nut 65 that is secured to the upper pressure .bar that is second from the right in the drawings. Similarly, the lateral adjustment screw 5I is threadedly engaged in a similar nut 65 that is secured to the opposed lower pressure bar 36.- Screw 43 is extended outwardly and has the hand wheel 13 for manually turning the screw. When an operator grasps the hand wheel 13 and manually turns it, he not only imparts rotary motion to the screw 43 but also to the sprocket 66 thereon and through the instrumentality of the chain 66 all of the other sprockets 63 are caused to ro-- tate and to turn their respective screws to advance or retract one set of vertically paired pressure bars, at all times maintaining complete alignment.

- In a similar manner, all other vertically paired pressure bars are moved laterally. It will, of course, be understood that before the inner disposed vertical pairs of pressure bars can be moved more than just slightly, the outer pairs will have to be laterally moved in the manner above described. Lateral adjustment is necessary for acommodating the machine to various widths of lumber that may be presented for gluing, so that at all times the heater elements can be maintained in alignment with the joint to which it is to be exposed.

Side pressure adjustment When a group of boards are disposed between the vertical pressure elements and the final gluing operation is to take place, not only must the panel being glued be subjected to vertical pressure, but it also must be subjected to side or lateral pressure. This is accomplished through the instrumentality of the longitudinally extending side pressure rails 63 which are carried by the carriage nuts 9I. The side pressure screw 94 has oppositely cut threads, one on each end, and a carriage nut 9| is threadedly engaged on each end. When the screw 94 is turned in one direction, for

' example, the carriage nuts and the side rails 93 may be brought closer together. Conversely when the screw is turned in the opposite direction the side rails will be drawn apart.

Power for advancing or retracting the carriage nuts 9I is supplied with relatively slow motion from the reducer gears 96 to which they are coupled. Power is supplied to the reducer gears 66 as has been described from the motor I62 through the longitudinal drive shafts I66 and I6I.

As can best be seen in Figures 4 and 7, the sprocket on each screw 94 is coupled, by means of the sprocket chain 96, to an adjacent sprocket 61 on a trunnion of the eccentric shaft 19. When power is applied to rotate the side pressure screws 94, the eccentric shafts are also caused to swing about the axes of their trunnions. This movement of the adjustment screw and of the eccentrics is only a part of a revolution approximately of one hundred eighty degrees. Swinging movement of the eccentric is converted into vertical movement for the upper tier of pressure bars 3|, to bring them downwardly into closer relation with the lower tier of bars 36, and to exert pressure on any boards that may have been disposed therebetween. The movement of the side pressure rails and of the upper tier of pressure bars is, of course, coordinated so that in the open position suflicient room is provided for the reception of unglued lumber or the removal of a glued panel and yet when they are brought closer together to exert pressure they will exert only sufficient pressure to hold the lumber being glued against twisting and displacement, and at the same time insure the complete spreading of the adhesive in the joint to effect secure an efiicient gluing.

Gluing operation Lumber is supplied to the assembly table, shown in Figures 18 and 20, ordinarily with one edge previously supplied with beads or strings of adhesive. It is usual in practice of my method of gluing to apply this adhesive some time previous to the gluing operation so that the adhesive will be dry or set up to a degree'that it will not smear or spread upon contact. The beads or strings of glue are applied only to-one edge of the boards, both of which are planed and smooth ready for joining.

-When the lumber arrives on the assembly and preheating table the unglued edges of the various boards are disposed downwardly in the slots I62 and are brought to rest upon the heater blocks I64 and adjacent the heater elements I65. The boards are thus associated edgewise with the heater elements long enough to receive heat and absorb it about an inch back from the unglued edge. This heating operation makes the, wood more receptive to the glue when it is later applied.

When the boards have been heated sumciently long enough for the practice of my method, they are laid on their sides upon the upper surface I6I forming the assembly table and arranged,

glued edg to adjoining preheated edge, in the manner in which they are subsequently to be glued together. When properly arranged, the laterally extending longitudinally movable traveler bar I54 on the assembly table has motion imparted to it through the instrumentality of the chains I53 which are driven by power applied to the sprocket I46 of the shaft I44. The flange I56 abuts against the ends of the long, narrow boards that have been roughly arranged for gluing, and shoves them forwardly off the assembly table and into the adjacent gluing machine. There the boards come to rest between the upper and lower tiers of vertical pressure bars.

Side and top and bottom pressure on the boards comprising a panel, together with the simultaneous application of intense heat along the joints, results in the production of an extremely strong, wooden panel that will withstand distortion from warpage and the like and which will have glued joints stronger than the actual material comprising the boards.

It may be that certain variations in thickness of the lumber being glued will occur, and for that reason I have mounted the bearings for the eccentric shafts for vertical movement against the plied to the lumber and the glued joint and would otherwise be trapped in the joint.

The removal of a glued panel, from the machine, when the pressure rails and bars are'withdrawn, is facilitated by the introduction of a new charge of unglued boards through the instrumentality of the pusher member I54. The glued panel is shoved outwardly from the end of the machine until it is engaged between the rolls "6 and I8 I. Roll.l|6 is a driven roll, and frictionally engages the under side of glued panel and draws it out of the gluing machine onto the supporting table or other mechanism that may be associated with the tail endof the gluing machine. The upper roll I8I may be flexed vertically against the tension of the spring I84, so that various thickness of lumber maybe accommodated between the two rolls and the rolls will be insured a secure grip on the glued panel.

Two forms of panels that can be produced by being glued in my gluing machine are illustrated normal downward urgence of gravity and of the springs 82, so that when the side pressure rails and the upper tier of pressure bars is given move- -ment no damaging pressures can be applied to the and distorting themselvesunnecessarily, which would destroy the alignment and accuracy required. To facilitate the dissipation of any heat I have provided the fluid conduits 34 through which water may be circulated to absorb and draw of! undesirable heat. The contact face of the insulator blocks associated with each heat element has lateral notches I98 as is clearly shown in Figure 12, to permit the dissipation of any steam that might be produced when heat is apin Figures 16 and 17. In the former a panel designated as a whole by numeral 260 composed of a plurality of longitudinal boards 21H have been glued together edge to edge as shown variously throughout the drawings. Each board "I of such a panel is prepared as indicated in Figure 21 by having rows or strings 202 of glue applied lengthwise along one edge. The other edge is rested on a heater block I64 and heat radiating from element I65 is absorbed into the board to make it receptive to glue as well as to later assist in softening the glue on an edge of another board that is brought into abutting relation thereto. Such panels may be produced in various widths but I prefer to form them about 54 inches wide as that lends itself well to subsequent milling or to use. Often panels thus formed out of a plurality of narrow boards may be later ripped into 14, 16 or 18 inch widths.

In Figure 17 an alternate form of panel 264 is illustrated, in which case side rails 205 are employed and one edge of each rail is grooved as shown at 206. Laterally of the rails and between them are glued short boards 201 which have had their ends tapered to fit the grooves 206 and be glued therein. Such a panel is practical for many uses in building construction as for sub-flooring, sheathing or finish panelling depending upon the quality of material used in it. The formation of such a panel permits preparation of lumber that would otherwise be too short for sale.

Having thus described my invention, I claim:

A gluing machine for a set ofboards consisting of a plurality of individual members to be joined edge to edge. which machine comprises a table having slots to receive the boards composing a set, heater means in said slots for heating edges of certain boards, pusher means across said table movable lengthwise thereof for advancing boards I 

